394005645 has 54 divisors (see below), whose sum is σ = 753473994. Its totient is φ = 190322880.

The previous prime is 394005643. The next prime is 394005701. The reversal of 394005645 is 546500493.

It is a happy number.

394005645 is a `hidden beast` number, since 3 + 9 + 4 + 0 + 0 + 5 + 645 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 16208676 + 377796969 = 4026^2 + 19437^2 .

It is not a de Polignac number, because 394005645 - 2¹ = 394005643 is a prime.

It is a super-3 number, since 3×394005645³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394005643) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 1464571 + ... + 1464839.

Almost surely, 2^394005645 is an apocalyptic number.

It is an amenable number.

394005645 is a deficient number, since it is larger than the sum of its proper divisors (359468349).

394005645 is a wasteful number, since it uses less digits than its factorization.

394005645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 394005645 is about 19849.5754362656. The cubic root of 394005645 is about 733.1071941612.

The spelling of 394005645 in words is "three hundred ninety-four million, five thousand, six hundred forty-five".